1. Field of Invention
The present invention relates to a method for a motion estimation algorithm. More particularly, the present invention relates to a method for a motion estimation algorithm based on block matching. The invention uses a low bit resolution oriented edge image, by which appropriate difference blocks for DCT coding are generated and encoding efficiency is enhanced.
2. Description of Related Art
Block-based motion estimation (ME) have been adopted to eliminate temporal redundancy of image sequence by MPEP1/2 and H.261, matched difference block for DCT coding is obtained under certain matching criterion. Due to high operation load of full search (FS), ME has been the main bottleneck in real time image encoding system, many fast ME algorithms have been developed to reduce the computation cost.
In most ME algorithms, sum of absolute difference (SAD) of luminance pixel is used as searching criterion, and results in the best matched difference block with global or local minimum energy, i.e., minimum direct current (DC) coefficients after DCT, but the alternating current (AC) coefficients might be large and encoding efficiency is reduced.